The shadow world of superstring theories
Abstract
Recent attempts to construct a superstring theory that unifies all the interactions of nature, including gravity, in a finite anomalyfree quantum theory have led to the speculation that there may exist another form of matter (`shadow matter') in the Universe, which only interacts with `ordinary matter' (for example, quarks, leptons) through gravity or gravitationalstrength interactions. The existence of shadow matter would have many astrophysical and cosmological implications, some of which are discussed here.
 Publication:

Nature
 Pub Date:
 April 1985
 DOI:
 10.1038/314415a0
 Bibcode:
 1985Natur.314..415K
 Keywords:

 Big Bang Cosmology;
 Gravitation Theory;
 Matter (Physics);
 Particle Theory;
 Quantum Theory;
 Unified Field Theory;
 Baryons;
 Broken Symmetry;
 Missing Mass (Astrophysics);
 Nuclear Fusion;
 Solar System;
 Astrophysics